As well known to those skilled in the art, mortar, “cement mortar”, consists of cement kneaded with water, and is often used as finishing materials of walls, floors, and ceilings. Furthermore, mortar is a relatively low-priced material, has desirable strength, fire resistance, water resistance, and durability, and is easily handled. Hence, mortar is being widely applied in various construction applications. Additionally, mortar is used to settle a masonry structure and as a plaster joint or plastering material. Thus, it must be used while its amount is controlled in a surface finishing process unlike concrete.
However, such mortar having excellent physical properties and frequently used as building materials, particularly, interior materials emits harmful substances capable of injuring dweller's health. Hence, in accordance with the recent trend of an increased interest in health, a study is being conducted to develop a composite capable of replacing such mortar, and for example, a study to replace mortar with clay becomes a prominent figure.
The clay consists of fine earth particles with a diameter of 0.004 mm or smaller, and is an aggregation including natural granules having plasticity when it absorbs moisture and having strength when dry. Additionally, the clay is apt to be sintered when being calcined at a predetermined temperature, and has a multi-layered honeycomb structure with large surface area. Further, far infrared rays are absorbed and stored in the pores of the honeycomb structure having a similar shape to a sponge, and when being heated, the clay emits the far infrared rays to stimulate molecular movement of a subjective material. Furthermore, a tea spoon of clay particles contains about two hundred million microorganisms, causing various enzyme reactions.
As described above, the clay emits far infrared rays contributing to activating physiological functions of cells and having a photoelectric effect which removes harmful substances from the cells using heat energy.
The clay has been typically used as building materials for walls or floors of buildings, finishing materials of interior and exterior parts of the buildings, and materials of tiled roofs. However, the clay has poor strength, water resistance, water tightness, and durability, thus being limitedly used as fireproof materials or calcined clay after being calcined. In other words, the clay is calcined to produce ceramic products with a desirable strength, and the ceramic products are used as the building materials and ceramic materials.
In the process of calcining the clay, a structure of the clay is melted by heat (traditionally, 1000° C. or higher) and converted into a hard glassy material, thereby preventing the clay from softening and allowing the clay to have predetermined strength. However, the process of calcining the clay is disadvantageous in that calcining the clay requires a high temperature which requires a lot of energy. Thus, there is the emitting of harmful pollutants due to the combustion of fuels which causes serious environmental pollution.
Additionally, when the clay is calcined so as to obtain a clay composite with desirable strength, the process of producing the clay composite is complicated, and the production time and cost of the clay composite are undesirably increased.